Construction Safety:Scissor Lifts

Scissor Lifts

• Aerial Work Platforms

• Classified by OSHA as Scaffolding

• Guidelines addressed in OSHA §1926.452(w) - Mobile Scaffolds– Must meet requirements of this section

Scaffolds

• Scaffold means any temporary elevated platform (supported or suspended) and its supporting structure (including points of anchorage), used for supporting employees or materials or both.

Statistics• More construction workers die from falling from a height above 6 feet

– Annual average 32-35%

• Average of 8 scissor lift fatalities each year• 10 year study conducted:

– Showed 40% of accidents occurred due to tip-over

• Many trades involved:– Painters– Drywallers– Electricians– Others

Top 10 Aerial Lift Fatality Causes 1. Operating on an uneven surface

2. Encountering holes, debris and drop-offs while operating elevated

3. Climbing above or leaning over the 42-inch minimum top rail

4. Overloading and collapsing the boom (i.e. using a manlift as a material crane)

5. Making contact with electrical conductors with an uninsulated portion of the lift

6. Neglecting to deploy outriggers or brace sufficiently against tip-over

7. Making body contact with electrical conductors or entering the induction field

8. Operating the lift in inclement weather or low visibility conditions

9. Inexperienced or untrained operators

10.Unobserved, uncorrected mechanical or structural defects in equipment

Scissor Lifts Accidents

• The most common types of accidents involving a scissor lift:– Tip-Over

• caused by misapplication of the machine, obstacles

– Misuse of the Equipment• Machines marked "Use on level surface only"• Used outdoors for the sake of economy or

availability, often resulting in tip-overs

– Lack of Maintenance

Industry Chronicles

• Salem, N.H., August 2007:– Two men on machine when it began to rock

back and forth• One worker grabbed onto roof pulling himself to safety

• The other worker went down with machine

– Scissor lift tipped over backward and fell to the ground

– Injured a 20-year-old construction worker, sent to hospital

– OSHA Investigation is underway

Industry Chronicles

• Garland, Texas, September 2007:– Construction worker on scissor lift was slightly

injured after a roof of a building he was working on collapsed.

– roof section fell onto the scissor lift– Operator was protected by the guardrails on the

lift. – The man was taken to the

hospital as a precaution.

Industry Chronicles

• Kansas City, Mo., October 2007: – A man was dismantling the steel frame of a

building when an I-beam fell on his scissor lift.

– Aerial lift fell over, dropping the man seven feet to the concrete floor below.

– Firefighters rushed to the scene and quickly freed the worker.

Safety Features

• Self-leveling platform or basket • AC/DC wired outlets in basket • Interlock control on safety gate • Tilt sensor-alarm • Built-in two-way radio and pothole protection • Motion alarm • Redundant foot control lock-out • Voltage “sniffer” and alarm

Accident Prevention

• Responsibility of the employee-designated competent person to evaluate the condition of the equipment.

• OSHA 1926.451(f)(3):– “Scaffolds and scaffold components shall be

inspected for visible defects by a competent person before each work shift and after any occurrence which could (potentially) affect a scaffold’s structural integrity.”

OSHA Accident Prevention

• The surface of the scissor lift being moved shall be within 3 degrees of level.

• Speed of scissor lift shall not exceed 1 foot per second.

3° max

Accident Investigation

• Perform an investigation as soon as an accident occurs

• Do not return the equipment (if rented) without documenting the incident first– Rental contractor contacted, sends out a replacement

unit, immediately removing and repairing the unit involved in the accident.

– Destroys the evidence "trail" before the investigation even begins.

Accident Prevention

• Use equipment on safe level ground only

• Do not overload equipment and/or use as a material lift

• Inspect installed safety equipment during a pre-start inspections– Document Defects, Repairs, and/or missing safety equipment;

notify rental contractor

• Obtain 12-month rental and repair history before renting the equipment

Accident Prevention

• Develop maintenance and documentation procedures for rental yard clients– Keep records for at least 3 years

• Emphasize the need to document pre-delivery and return inspections

• Training– Allow time to instruct for safe operation of machinery– Operations Training